Nishikori, who broke Cilic's opening service game, said it was important that he made a mark early in the match.

"The tactics were to hit good returns and make whatever I could from his serve, especially his first serve," Nishikori said.

"I guess his first serve percentage was low today, so that helps too."

Nishikori said he was prepared for a tough game against Hewitt.

"He's always tough to play - he doesn't miss much," Nishikori said of Hewitt.

"It's not easy (to play him) because he has decent serves and a good return and good backhand - very solid on groundstrokes."

Azarenka into women's final

World number two Victoria Azarenka survived a scare against Jelena Jankovic to be the first to qualify for the Brisbane International women's final on Friday night.

Second seed Azarenka, 24, eventually outlasted former world number one Jankovic 1-6, 6-3, 6-4 and will take on the winner of Friday night's semi-final between arch rivals Serena Williams and Maria Sharapova.

The fourth-seeded Belarusian stumbled ahead of her Australian Open title defence when she was overwhelmed in the first set and was forced to weather a spirited fightback from Jankovic in the third.

Azarenka led 5-1 in the third set before Jankovic reeled off the next three games.

It sounded alarm bells for the two-time Australian Open champion who blew nine match points in her three set quarter-final win over Switzerland's Stefanie Voegele.

But Azarenka dug deep to hold out world number eight Jankovic in just over two hours at Pat Rafter Arena.

It was a set back for former US Open finalist Jankovic who broke back into the world top 10 the hard way in 2013, playing 20 main draw events and notching an impressive 46 wins for the year.